Radio loud speaker



Patented Feb. 16, 1932 UNITED STATES CHARLES HUGH DUFFY, OF MIAMI, FLORIDA RADIO LOUD SPEAKER Application filed September 28, 1981.

Serial No. 565,584.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, AS AMENDED APRIL 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

5 This invention relates to radio loud speakers and the like, and has for its principal object to effect a combination or arrangement of parts whereby a vibratory diaphragm of the type to be described may be actuated by two I) or more actuating units or electrical impulse responsive devices, without having imparted to such diaphragm improper transverse vibrations caused by transverse buckling of the diaphragm. 1 '15 In diaphragms of the type to which this is particularly directed, the actuating unit or electrical impulse responsive device is connected to the central meeting edge portion of the two flexed diaphragm formations, and B when two or more actuating units are employed, they are each connected to said central meeting edge portion of the diaphragm one under the other as proposed in my United States Letters Patent Numbered 1,7 40,161 of December 17 1929 and 1,812,867 of July 7 1931.

When actuating units or electrical impulse responsive devices which have pivoted transfer levers are employed, the impulses are delivered to the diaphragm in arcuate directions and when more than one such actuating units are imparting independent pulsations to a diaphragm in independent arcuate directions, that part of the central meeting edge portion of the diaphragm which is directly between the points of connection of the actuating units with the diaphragm is subjected to forces tending to alternately elongate and compress such intermediate portion of the diaphragm in the direction of its length. Under certain conditions, this causes the intermediate portion of the diaphragm to buckle transversely and take on an improper transverse vibration which is detrimental to the purity of the reproduced sound.

This invention has for its object to avoid such transverse movement of the diaphragm and to limit the vibratory movement of the diaphragm to the exact pulsations impressed upon it by the actuating units or impulse responsive devices and thus eliminate unnatural resonance and the formation of detrimental harmonics.

Referring to the accompanying drawings Figure 1 is a diagrammatic view of the pivoted transfer levers of two actuating units and schematically illustrating them connected together by a rigid connection;

Figure 2 is a diagrammatic View of another example of the pivoted transfer levers of two actuating units and schematically illustrating them connected together by a rigid connection;

Figure 3 is aconstructional view in side elevation of a diaphragm and two actuating units embodying the principle diagrammatically illustrated in Flgure 1;

Figure 4 is a constructional view in side elevation of a diaphragm and two actuating units embodying the principle diagrammatically illustrated in Figure 2, and

Figure 5 is a horizontal sectional view taken on line 5-5 of Figure 3.

Like numerals of reference indicate the same parts throughout the several figures, in which:

1 indicates the vibratory diaphragm of two flexed substantially quarter-circle or partially circular formations 2, and 3 and f illustrate the actuating units or electrical impulse responsive devices.

Referring to Figure 1 it will be seen that the normal arcuate movements at the points of connection 5 of the transfer levers with the diaphragm would be as indicated by the dotted arrows, but that if the points of connec tion 5 were connected together by a freely vibratable but rigid connection 6, said connection 6 would move or vibrate with the two transfer levers 7 and their connecting links 8, but that the rigid connection 6 would resist any transverse buckling or bending between the two points 5.

Applying this diagrammatic illustration to Figure 3, it will be seen that the central 95 meeting edge portions 9 of the two flexed diaphragm formations are extended a considerable distance behind the line of juncture 10 of the two flexed formations and that a stiffening filler piece 11 (Figure 5) of suit 100 able material is interposed between the ex- 5 is on a downwardly bent are as in Figure 1,

tended central meeting edge portions 9 to space the same apart and to give to the structure, particularly between the connecting points 5, a rigidity suficient to resist transverse bending or buckling of the central meeting edge portion of the diaphragm between the said connecting points, and thus resist the formation of any improper sidewise or transverse vibration due to alternate forces tending to lengthwise elongate and compress that intermediate portion between the points 5 under the influence of the normal arcuate movement at the points 5. I

The diaphragm 1 is as shown in Figures 3, 4 and 5, preferably flexed into two substantially quarter-circle formations, and the side edge of each flexed formation is clamped as at 12. This clamping ,of the side edges of the diaphragm causes the entire diaphragm including the rigid portion to which the actuating units'are connected,- to resist any vertical movement or movement in the direction of'its length. Consequently the connecting links 8 from the transfer levers 7 of the actuating units, are slightly flexible so that the tendency of the diaphragm to resist movement in the direction of its length and thus follow the normal arcuate movements of the points 5 is compensated by the slightly flexible connecting linksS so that the normal arcuate movements at the points 5 are straightened out and become substantially perpendicular to the vertical axis of the diaphragm as indicated by the straight arrows in Figure 3, and this without causing any sidewise or transverse buckling or improper transverse vibration of the rear rigid edge portion of the diaphragm. It is to be understoodthatnthe term rigid as used here is only relative. It does not mean that the rear portion of the diaphragm may not be bent transversely by manual means, or by any force superior to that exerted by the actuating units. It simply implies rigidity in the sense that it is capable of effectively resist ing any tendency to buckletransversely or to take on false transverse vibrations under the influence of the actuating units, since the intermediate part 6 is the equivalent of the rigid connection 6 of the diagrammatic assembly of Figure 1.

Now with respect to the example illustrated in Figures 2 and 4, the action is somewhat different, as will appear from a consideration of the diagrammatic Figure 2. In this instance the two pivoted transfer levers 'Z' are reversed with respect to each other and their links 8 are connected to a rigid member 6 which, as in Figural, is capable of movementin response to movements of the transfer levers but is suiiicientlyrigid to effectively resist any transverse buckling or bending throughout its length. The normal tendency of movement at the upper point of connection but the normal tendency of movement at the lower point of connection 5 is on an upwardly and oppositely bent arc. If the element 6 connecting these two points 5 was flexible and elastic the actual movements at the points 5 woulc. be along these oppositely bent arcs, and the result of these movements would cause the connecting element 6 to very positively bend or buckle transversely when the movements were positive or in the direction of the connecting element 6. When these movements were negative or in the direction away from the connecting element 6, the result would cause the connecting element to elongate, and there would be alternate bending and elongation of the connecting element 6. Considering, however, that the connecting element 6 is rigid to effectively resist this alternate bending and elongation, the result of the movement at each of the points 5 will be in substantially straight lines, as indicated by the straight arrows in Figure 2, and which are perpendicular to the vertical axis of the connecting element 6. v

. Applying this to the structural illustration in Figure 4, wherein the actuating units?) and 4 are shown reversed, it will be seen that when that part 6 of the meeting edge portion 9 of the diaphragm 1 which is intermediate tively resist the alternate transverse bending and stretching moments imparted to the diaphragm, the movements at the points 5 will be in substantially straight lines as indicated by the straight arrows in Figured, which means that the pulsations impressed on the diaphragm by the actuating units will be in a direction perpendicular to the vertical axis of the diaphragm and not in theirnormal arcuate direction and without buckling. the intermediate portion 6 transversely. or creating any false transverse vibrations in the diaphragm.

It will be understood that in the two em bodirnents described, the longitudinal axes of the pivoted transfer levers 7 of the actuating units lie in the same plane with the central vertical or longitudinal axis of the diaphragm, so that the normal arcuate movements if present at the connecting oints would also lie in the same plane." The actions of the actuating units on the diaphragm are different from those disclosed. in my copending application Serial Number 529398 wherein the longitudinal planes of the pivoted transfer levers lie transversely of the central vertical or longitudinal axis of the diaphragm. The problems to be met in the aresent instance are different from those in the former case.

Having thus described the invention, itis to be understood that while I have illustrated and described onlyone example of a construction for imparting the necessary rigidity'to the connecting points 5 is rigid so as to eifec;

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the central meeting edge portion of the diaphragm, other means may obviously be employed for effective cooperation with the plu rality of actuating units.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a radio loud speaker or the like, the combination with a vibratory diaphragm including two flexed substantially quarter-circle formations having side edge portions and a central meeting edge portion, the central meeting edge portion of each formation being extended beyond the line of juncture of the two formations and a stiff member interposed between the extended portions of the diaphragm formations to impart rigidity thereto and to space the same apart, of two actuating units, each having a pivoted transfer lever reversed with respect to each other, the longitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, flexible connecting links for connecting the actuating units to the meeting edge portion of the diaphragm, said meeting edge portion of the diaphragm which is intermediate the points of connection of the actuating units therewith being rigid to resist transverse buckling of the diaphragm intermediate the two actuating units.

2. In a radio loud speaker or the like, the combination with a vibratory diaphragm including two flexed substantially quarter-circle formations having side edge portions and a central meeting edge portion, the central meeting edge portion of each formation being extended beyond the line of juncture of the two formations and a stiff member interposed between the extended portions of the diaphragm formations to impart rigidity thereto and to space the same apart, of two actuating units, each having a pivoted transfer lever reversed with respect to each other, the longitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, means for connecting the actuating units to the meeting edge portion of the diaphragm, said meeting edge portion of the diaphragm which is intermediate the points of connection of the actuating units therewith being rigid to resist transverse buckling of the diaphragm intermediate the two actuating units.

3. In a radio loud speaker or the like, the

. combination with a vibratory diaphragm including two flexed substantially partially circular formations having side edge portions and a central meeting edge portion, the central meeting edge portion of each formation being extended beyond the line of juncture of the two formations and a member interposed between the extended portions of the diaphragm formations to impart rigidity thereto and to space the same apart, of two actuating units, each having a pivoted transfer lever reversed with respect to each other, the longitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, means for connecting the actuating units to the diaphragm, the meetin edge portion of the diaphragm which is intermediate the points of connection of the actuating units being rigid to resist transverse buckling of the diaphragm intermediate the two actuating units.

4. In a radio loud speaker or the like, the combination with a vibratory diaphragm including two flexed substantially partially circular formations having side edge portions and a central meeting edge portion, means at the central meeting edge portion for imparting rigidity thereto, of two actuating units, each having a pivoted transfer lever reversed with respect to each other, the longitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, means for connecting the actuating units to the diaphragm, the diaphragm portion which is intermediate the points of connection of the actuating units being rigid to resist transverse buckling of the diaphragm intermediate the two actuating units. i

5. In a radio loud speaker or the like, the combination with a vibratory diaphragm including two flexed substantially partially circular formations and a central meeting edge portion, means for spacing apart the central meeting ed es of the two flexed formations of two. actuating units, each having a pivoted transfer lever reversed with respect to each other, the longitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, means for connecting the actuating units to the diaphragm, the diaphragm portion which is intermediate the points of connection of the actuating units eing rigid to resist transverse bucklin of the central meeting edge portion intermefiate the two actuating units.

. 6. In a radio loud speaker or the like, the combination with a vibratory diaphragm including two flexedsubstantially partially circular ormations and a central meeting edge portion, of two actuating units, each having a pivoted transfer lever reversed with respect to each other, the longitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, means for connecting the actuating units to the diaphragm, the portion of which is intermediate the points of connection of the actuating units being rigid to resist transverse buckling of the diaphragm intermediate the two actuating units.

7. In a radio loud speaker or the like, the combination with a diaphragm including two flexed substantially partially circular formations having a central meeting edge portion, of two actuating units, each having a pivoted transfer lever reversed with respect to each other,-thelongitudinal axes of which levers lie in the same plane with the central longitudinal axis of the diaphragm, and means for connecting the actuating units to the dia- V P m I a 8. In a radio loud speaker or the like, the combination with a diaphragm flexed into two substantially partiallycircular forma- 10 tions and having a central meeting portion,

, the diaphragm formationsbeing extended beyond the line of their juncture, a stiff member interposed between the extensions of the formations to impart rigidity to the central meeting edge portion and to space the formations apart, of two actuating units, and means for flexibly connectingthem to the central meeting edge portion one under the other, that part of the central edge portion intermediate the points oficon'nection of the two actuating units beingrigid' to resist transverse buckling of the diaphragm intermediate the two actuating units. V

9. In a radio loud speaker or the like, the

'25 combination with a diaphragm flexed into two substantially partially circular vformations and having a central meeting edge portion, of two actuating units, means for connecting themto the diaphragm one under the other,

and means at the'central-meeting edge por- I tion of the two flexed formations for spacing apartthe meeting edges of the two flexed for mations, said spacing means being rigid to 7 cause the diaphragm to resist transverse buckling intermediate the two actuating units. 7

10; In a radio loud speaker orthe like, the

combination with a diaphragm flexed into two substantially partially circular formations .40 and having a central meeting edge portion, of

two actuating units, means for connecting them to the diaphragm one under the other, rigid means at the central meeting edge portion of the twofiexed formations for causing 15 the diaphragm to resist transverse buckling of the central meeting edge portion intermediate the two actuating units. 7

In testimony whereof I affix my signature.

' CHARLES HUGH DUFFY. 

